He said: "It is impossible for us to truly comprehend what Jessica endured.

"What I am sure of, however, is that Blackburn fully understood the consequences of his actions, acted without a glimmer of fear or compassion and ultimately showed a contemptible disregard for the agonies of someone he claimed to care for."

The area Procurator Fiscal for Tayside, Tom Dysart, said the crime had provoked outrage in the local community.

He said: "Jessica's family and friends not only have to live with her tragic loss, but also to carry the knowledge of the terrible circumstances in which she died.

"I hope that they can take some comfort from the jury's verdict, and from the fact that Stewart Blackburn has now been brought to justice."

Lord Bracadale called for background reports on Blackburn, who has a string of convictions for theft by housebreaking and assaulting Jessica's father.